Noise reduction system with chamber

Abstract

A noise reduction system with a chamber includes a chamber (17) which is provided at a portion of a supply path connecting a flow path in an upstream side of a combustor in a jet engine to a plurality of microjet nozzles which is provided at an exhaust side peripheral edge of a main nozzle of the jet engine, wherein the supply path is configured to supply part of compressed air from the flow path into the chamber (17), and the chamber (17) is configured to inject the compressed air through the plurality of the microjet nozzles (63) to a jet flow.

Description

TECHNICAL FIELD[0001]The present invention relates to a noise reduction system used for a jet engine of an aircraft.[0002]Priority is claimed on Japanese Patent Application No. 2009-247780, filed on Oct. 28, 2009, the contents of which are incorporated herein by reference.TECHNICAL BACKGROUND[0003]A jet engine of an aircraft includes a fan to take air therein, a compressor to take in and compress part of the air taken by the fan, a combustor to mix compressed air generated by the compressor with fuel and to combust the mixture, and a turbine to drive the fan and the compressor by using combustion gas from the combustor, which are all arranged in sequence.[0004]The compressor, combustor and turbine are installed in a main nozzle as a cylindrical partition, and the fan is placed in the upstream side of the main nozzle. Most of the air taken by the fan flows through a bypass flow path which is provided between the main nozzle and a casing (an engine nacelle) covering the outer peripher...

AI Technical Summary

Benefits of technology

[0031]According to the present invention, a space from the flow path in the upstream side of the combustor to the microjet nozzle can be set large. Accordingly, the pressure loss by using a conventional pipe can be reduced, the microjet can be injected uniformly in the circumferential direction by uniformly pressurizing the chamber, and it is possible for noise to be efficiently reduced.

[0032]In addition, because the chamber is installed instead of the pipe, in response to removal of the pipe, damage to the pipe by heat of the jet engine can be avoided, and the displacement of the placement position thereof can be prevented.

[0033]Further, because the structure of the chamber is simple, the chamber can be more easily installed than installing operations of the pipe. Therefore, the assembling workability thereof can be improved.

[0034]In addition, the exposure of the pipe can be reduced at the outer peripheral surface of the main nozzle. Accordingly, the cavity flow can be suppressed in response to removal of the pipe, and the additional noise in connection with vibration of the pipe can be avoided. The nacelle resistance can be reduced, and thereby the aerodynamic performance of the jet engine can be improved.

[0035]Further, the distance from the chamber to the tip of the microjet nozzle can be set short, and thus the pressure loss of the compressed air can be more reliably reduced in response to shortening of the distance. Therefore, it is possible to inject the microjet more efficiently.

Problems solved by technology

The area where the jet flow and the bypass flow join to each other becomes a noise source, and thus noise occurs.

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